Two highly recommended books which have chapters on setting up network services:
Dru Lavigne,
The Best of FreeBSD Basics
Michael W. Lucas,
Absolute FreeBSD
Both should be available on Amazon and elsewhere.
The time it takes to produce a book being what it is, neither of them is completely current with FreeBSD 8.0. But the nice thing about FreeBSD, unlike a proprietary OS like Windows that uses planned obsolescence to drive sales, is that almost everything in these books about older versions of FreeBSD still applies.
And of course, the
handbook will often be your first and best resource.